Lego gives insight into microscopic movements

Scientists trying to visualise microscopic activity are using Lego bricks to simulate the behaviour of nano-particles on a slightly larger scale.

The peg-like Lego bricks have been pressed into action by Johns Hopkins University researchers investigating how cells and other small particles move through tiny sorting devices called microfluidic arrays. Also known as labs on a chip, these are used to sort tiny samples by shape, size or composition.

The scaled-up version consists of Lego pegs stacked two high on a Lego board to create a grid of obstacles. The board was then mounted on a Plexiglas sheet and pressed up against one wall of a tank filled with glycerol to slow their movement, Science Daily reports.

The team released three different sizes of stainless steel and plastic balls into the top of the lattice and filmed their paths to the bottom of the tank. They also rotated the array so that gravity was pulling at them from a different angle, but they found that the particles moved in the same direction regardless of the angle.

The team said that this was likely to apply in microscopic systems too. "There are forces present between a particle and an obstacle when they get really close to each other which are present whether the system is at the micro- or nanoscale or as large as the LEGO board," Joelle Frechette, assistant professor of chemical and biomolecular engineering, said.

Her colleague, German Drazer, said the results were significant: "Our experiment shows that if you know one single parameter – a measure of the asymmetry in the motion of a particle around a single obstacle – you can predict the path that particles will follow in a microfluidic array at any forcing angle, simply by doing geometry."